NES,SEGA and GB music on the C64 ???
a surprise to myself... and maybe a for a few of you too. In 1998, Chris Covell decided he needed to play PSG .SND format music on the Commodore 64 SID chip, so he programmed NESSIDPlay, a little program that allowed you to play NES, Sega Master System and Gameboy tunes (extracted from an emulator) directly on your Commodore 64, featuring 4 NES channels somehow squashed into the 3 SID channels. Not a bad idea my friend !
Apparently it died somehow because the .PSG format changed to standard MIDI files. So the project hasn't been updated since a while.. not 100% sure of the story
Haven't tried it yet so I can't comment on the actual results .. just thought of how cool to hear the original nintendo and sega sequences on the SID...
Chris explains how the NES sound chip compares to the SID:
... there is very little comparison. The NES has more sound channels, but is highly primitive. The SID has synchronization, ring modulation, filtering, resonance effects, etc to its benefit. The NES has 5 sound channels: 2 square wave, with only 4 selectable duty cycles; 1 triangle wave; 1 noise channel; and 1 DMC sample channel. These assignments are fixed. Frequency is controlled through an 11-bit combination of registers, and volume is controlled through a 4-bit volume register. To its advantage, the NES can play 7-bit samples through its sample channel.
The SID has only 3 sound channels, but each can be selected to play any combination of square, triangle, sawtooth, or noise waveforms. Frequency is controlled through a 16-bit combination of registers; and pulsewidth is controlled through a 12-bit combination of registers. The SID has a sophisticated ADSR method of controlling a note's volume and shape as it is being played. Added to that is an 11-bit highpass, lowpass, or bandpass filter, which through subtractive synthesis can produce very complex and realistic sounds, like an electric guitar, string bass, techno-bleeps, you name it. Furthermore, channels can be combined to produce modulation effects such as vibrato or tremolo. The SID also has a way of producing sampled sounds, though I believe they are only 4-bit...